Gunnery training device



Jan. 25, 1949. R, B, BUCHANA 2,459,867

GUNNERY TRAINING DEVICE Filed Oct. 12, 1945 2 Sheets-Sheet 1 FIG! 5a 49 A T TORNEY DMD SE28 QHGRR as m 24:33: MG 7 wumvmu 1949- R. B. BUCHANAN GUNNERY TRAINING DEVICE 2 Sheet-Sheet 2 Filed Oct. 12, 1945 it Sw Ewtwm Hul INVENTOR By R B. BUCHANAN @6. M

A TTORNEV Patented Jan. 25, 1949 Russell 3. Betta-name. -N.,

to Bell 'relepnane' La oratories, ,l"nco as s ijgnor rp'orated,

New Ydrli, N. Y., acorporation of'New'York etppiicationoctober 12, 1945, Serial No. 622,066-

This invention relates to an operationalifil i fitrainer and more particularly to circuits and apparatus for simulating the control of the guns of an" airplane. I e I airplane of the fighter type, which the trainer is designed to-simul ateinay be providedwith a plurality of guns. For the-sake of safety when the airplane is on the carrier deck, air field, or in formation flight but not in actual combat; the guns are not charged with shells. The charging mechanism of these guns is hy-" draulically operated by pressure supplied fromsuch chargersare provided; one for charging the guns on the left Wing and the other for charg-' ing the; right guns.

To charge the guns under its control the gun charger knob is turned to'the Charge position andthen depressed; The turning of the knob opensa valve allowin oil in the hydraulic system to enter the guncharging systemof the as socia'ted guns. The knob when depressed is locked in itsdepressed position; The appl-ica tion of pressure tothe gun charging system causes the gun charging cylinders of the guns topull out the bolts and allows the gun charging mechanisms of the guns to receive shells which will be forced into the breeches whenthe bolts are later released. When the hydraulic pressure inthe gun charging valve builds up to about 800 pounds per square inch, the valve will open the release port thereof and the gun char ing knob will snap out. This releases the pressure in the charging cylinders of the guns allowing the bolts to restore and forcin'g'th'e' shells into the breeches of the guns. The guns are then ready to be fired.

To safety the guns the gun charger knob is turned to the Safety position and therfdep'ressed. The turnin of the knob opens the valve to" allow oil in the hydraulic system to enter the gun charging system of the associated guns. The knob when depressed is locked in its depressed position. The application of pressure to'thegl'in chargin system causes the gun charging'cyliri ders of the guns to pull out the bolts as theydid for charging. When the hydraulic pres's'urein the gun charging valve builds up to about 800 pounds per square inch the gun charging lfiob' reclaims. toilet-25) 2 wilt snap outbu't the valve does not open the release 'pert of the valve. Therefore the'bo'lts-will' remain out and the breeches will remain open anglthe unsaresafe. Turnin the gun chargin knob to thecharge position after the guns'have been safetie'd willopen the release port of the valve thus releasing the pressure in the charging cylinders; of the guns-allowing the bolts to restore andclosing the breaches of the guns eyen though the lirigilgi is; not depressed in the Charge position. Also after the guns are once charged or safetied'; fai re of the hydraulic system will not prevent clialg 'ngi the guns but an mate itirnpossible to safetythjem l v f It is the objecto'f the'p're'sent-invention to simulate fe' charging afid'safetying of the guns of an an'plahe a ground trainer for pilot training.- aZ ra-mer a isnot .d sirable to provide the espe giiris whi cliwouldthe armament of an aerial airplane orto proVide hydraulic systeiri'yvh'icti' would be reguired'to' furnish the inseam-1e" sewer necessary to charge and Safety the gt tend'and retract the landing gear, to o erate thewin fi'aps, to operate the engine etwr fi aps to operate the inter-cooler a d" oil shutters and to? operate the wing locking g m r e-e. s mp e n 'l sl iv'e ectrical quip n s provided whichsimulates the productionof the requisite hydraulic pressure, which. simulates the-pressure controls exercised by the gun charger valves and which simulates the response s of the gun mechanisms.

v In-erder that ill'SO far as the pilot-under training is concerned, the gun chargersgwhich" are mounted on the pedestal in the cockpit of the trainer shall. have the same appearance and shall appearto function in exactly-the same man ner as-those installed inthe c'ockpit'of an arc-- t-ual: airplane; each gun charger valve, used in the actuala'irplane-which the trainer simulates, has'been'rnodified by the removal of an piping connections thereto; bythe addition of-a switch operable'when thezc harging kriob'i's"turned to its Gharge positionpor air-switch operablewhen the knob: is depressed when turned to the Charge pos'itiori'wo'f a switch operable' when" the kn'ob'is turned to its" Safety position; of a'switch o'p'erabie" when the knob is"c1stressed wh'e' turnedto" its safety positron;-

by the a tide of a solenoid release for thekn'ob to replace the pres sureoper'atedrelease.

net at betterunderstanding or the" invention" of the valve stem and two of the switch assemblies operable thereby;

Fig. is a detail view in cross-section of the solenoid operated detent for locking the knob and valve stem in their depressed position; and

Fig. 6 is a diagram of such circuits and apparatus of the trainer as are deemed essential to an understanding of the invention.

The gun charger valve disclosed in Figs. 1 to 5, inclusive, comprises a casing I having a valve stem bore 2 extending therethrough, two downwardly extending valve bosses 3 and 4 and two horizontally extending valve bosses 5 and 6. The bosses 3, 4 and 5 are provided with holes therethrough which connect with the valve stem bore 2. The outward portions of the holes are threaded to enable connection with pipes of the hydraulic system. Since, however, no piping is connected with the valve in the trainer, these threaded holes are closed by the screw-threaded plugs 1, 8 and 9. The plugs 1 and 8 are slotted so that they may be screwed into the holes in the bosses 3 and 5. The plug 9 which screws into the hole in the boss 4 is provided with a hexagonal head for the purpose of securing the horizontal arm 10 of the L-shaped, bracket 1 l to the end of the boss 4.

Slidably and rotatably supported in the bore 2 of the valve casing I is a valve stem [2 in the forward end of which the handle I3 is secured by the pin [4. Surrounding the forward end of the valve stem is a cup-shaped collar the cylindrical portion of which is slidable within the chamber portion 16 of the bore 2. Positioned at the rear of the chamber l6 and surrounding the stem [2 is a sealing member l1 which is retained assembly shown more in detail in Fig. 5. This assembly comprises a chambered cap screw 24 threaded into the tapped hole in the boss 6 and having a detent 25 slidably supported in the chamber thereof. The detent has a detent stud 26 engageable against the shoulder 23 of the stem l2 by the spring 21. The spring 21 is positioned within the chambered portion of the detent 25 and bears against the outer end wall of the chambered portion of the screw 24 and against the lower end wall of the chambered portion of the detent.

Secured to the detent 25 is a rod 28 which extends outwardly through a hole in the end of the cap screw 24 and have a retainer 29 secured to the outer end thereof. Clamped to the cylindrical end 30 of the cap screw 24 is a bracket 3|. The bracket is L-shaped, the short leg 32 thereof being provided with a hole therethrough to enable such leg to be slipped over the end 30 of the cap screw and having a saw cerf extending from such hole to one edge of the le with a screw 33 extending through the two portions separated by the saw cerf to enable the bracket to be clamped to the cap screw. Pivoted to the long leg of the bracket by the pin 34 is a downwardly extending link 35, the upper end of which bears against the inner face of the retainer 29.

The lower end of the link 35 is pivoted by the pivot pin 36 to the outer end of the core 31 of a solenoid. The solenoid has a U-shaped heel-piece 38 of magnetic material to the base 39 of which is secured a cylindrical sleeve 40 of non-magnetic material which extends within the arms of the in the rear end of the chamber by the snap ring l8. Surrounding the stem 2 and positioned between the outer face of the member l1 and the inner face of the collar 15 is a return spring 43 which is tensioned to thrust the collar 15 outwardly against the pin [4 secured to the stem I; to thereby move the stem to its normal or extended position.

The stem [2 also is provided near its outer end with a detent l9, shown in dotted lines in Fig. 2, the head of which normally rests against the outer face 20 of the casing l to prevent the valve stem from being pressed inwardly by the handle l3 unless the handle is turned into either the Safety position illustrated in Fig. 2 or into the Charge position indicated by the dotted position of the handle [3 shown in Fig. 2. In either of these positions the stud [9 will be aligned with slots in the casing extending parallel with the axis of the stem l2 and the handle l3 may then be depressed to move the stem longitudinally through the bore 2. The stud I9 is illustrated in Fig. 2 as aligned with one of the slots when the handle I3 is in the Safety position, and the other slot 2! with which the stud l9 becomes aligned when the handle is in the Charge position is indicated by dotted lines in Fig. 2.

The valve stem just back of the chamber I6 is provided with a reduced portion 22 having a shoulder 23. Mounted in the boss 6 is a detent heel-piece and parallel thereto, and within which the core 31 is free to slide. Surrounding the sleeve 40 is the solenoid coil 4|. The solenoid assembly is supported with the outside of its upper heelpiece arm-against the outer end of the boss 3 by the horizontal arm H) of the bracket I I, the lower arm of the heel-piece 39 being secured to the arm l0 by the screws 42,

When the knob I3 is turned to either its Charge or Safety position and then depressed, the detent 26 is forced by the spring 21 into engagement with the reduced portion of the valve stem [2 so that when pressure on the knob 13 is released the shoulder 23 of the stem engages the detent and the stem is thereby held in its depressed position. To permit the stem to be returned to its normal position by the return spring 43, the coil 4| of the solenoid is energized to attract its core 31 and through the pivoted link 35 to cause the detent 26 to be pulled out against the tension of the detent spring 21 to release the valve stem I2.

' Secured by a screw 44 to the rear end of the valve stem I2 is a cam member 45. The end of the cam member is provided with a tubular cam extension 48 which extends through substantially 200 degrees of the circumference of the member 45. Positioned to be operated by the rotation of the cam extension 46 are two spring assemblies A and C and positioned to be operated by the cam extension 46 when the valve stem I2 is depressed are two other spring assemblies B and D. Each of these spring assemblies comprises three springs the two outer springs being fixed to serve as front and back contact springs and the middle spring being normally engaged with the back contact spring and having a stud 41 of insulating material extending therefrom by which such spring may be forced out of engagement with the back contact spring and into engagement with the front contact spring. These spring assemblies are illustrated schematically in the lower mugged? 5 portion of Fig 6; the back contact position: of each assembly being indicated by the letter and the front contact position by the letter 0.

For supporting the spring assemblies A and C the L-shaped bracket ll, hereinbeiore' referred to, is provided, which bracket has its horizontal arm l0 secured to the end of the boss 4 of the valve. casing i by the cap screw 9 and has its vertical arm 48' clamped to the end of the casing l bythenut 49' which is threaded on toa threaded extension 59- of the casing. The arms N] and are provided with suitable holes through which the'cap'screw 9 and the threaded extension '0"extend. To space'the arm iii of the bracket properly to permit the solenoid assembly to be supported between the arm Hi and the end of the boss 3, a tubular spacer 51 is interposed between the end of boss 4 and the arm ID of the bracket.

The spring assemblies A and C are secured to the vertical arm 48'- of the bracket H' by bolts' 52 which extend through the assemblies and through tubular spacers 5'3 and through holes in the bracket.

For supporting the switch assemblies C'and'Da U-shaped horizontal bracket 54 is provided the ends of the arms 55 and 56 of which are bent at right angles to form feet 5! and 58' by which the arms are secured by'screws 59 to the bracket H near the upper'edge of the vertical arm 48 thereof. The spring assemblies are secured to the outer end of the bracket 54' by bolts 6'0.

When the knob i3 is in the Safety position as illustrated the cam extension 46 is moved into such a position. that the switch assembly C is operated to its alternate or 0 position and the other switch assemblies A, B and C remain in their normal or 0 positions. If the knob I3 is now depressed while in the Safety position, the switch assembly C remains operated to the: 0 position and in addition the engagement of the edge of the cam extension 46 with the stud 41' of the switch assembly D operates such assembly to its alternate or 0 position.

When the knob i3 is rotated to the Charge position the cam extension 46 is-movedinto-such a position that the switch assembly C is permitted to release to its normal or 0 position and switch assembly A is operated to its alternate or 0 position and the other switch assemblies B, C and D remain in their normal or 0' positions. If the knob i3 is now depressed while in the Charge position, the switch assembly A remains operated to the 0 position and in addition the engagement of the end of the cam extension 46 with the stud 4'! of the switch assembly B operates such assembly to its alternate or 0 position.

Referring now to Fig. 6 in which the circuits which embody the invention are disclosed, the switch assemblies A, B, C and D of the gun charging valve which in an airplane would control the guns mounted in the right wing, are disclosed schematically in the lower portion of the drawing. The SF; SFl, CH, CHI, CH2 and RLS-relays 600 to 685, inclusive, operable by the spring assemblies are provided to simulate the charging and safetying of the right guns. Similar switch assemblies and relays would. be provided for simulating the charging and safetying of the guns which would be mount-ed on the left wing of an actual airplane- All ofthese relays together with the other relays disclosed in: the drawing are mounted in relay racks in the apparatus cabinets for the. trainer which! cabinets are connected to 6 the m'ock-upof the fuselage and with an instructors desk by cablesof conductors.

The group of: relaysincluding the INBD, MID and OTBD relays d31 3081 and 669 are selectively operable underthe control of the Inboard-Middle and Outboardgun selector switches. 6H, 6H and 613 mounted on the electrical distribution panel in the cockpit, to enable thepilot to select the Inboard, Middle or Uutboard guns-for firing. The Master armament switch 64 4 also mounted on the electrical distribution panel controls the MA relay 606 torend-er the trigger M5 mounted on the control switch: of the airplane effective to simulate the firing or any of the guns.

The apparatus enclosed within the dot-dash rectangle in the right portion of the figure shows such apparatus at ani'nst'ructors desk as concome the supervision of the pilot in simulating the handlingof the guns.

The apparatus which embodies the invention having now been discussed, consideration will now be given to the manner in which the apparatus functions under a pilots control to simulate the operations of the guns of an airplane.

To prepare the trainer for a simulated flight the pilot closes the Battery switch located on the electrical distribution panel in; the cockpit thereby establishing an' obvious circuit for the MB relay 6 111 which, upon operating, connects battery and ground tothe battery and ground bus bars 6 l6 and Gil. Assoon as-the-simulated starting of the engine has been completed and the engine has assumed asimulated speed of 1,300 R. P. the GEN relay ti? operates and supplies battery and ground to the bus bars 655 and 617, in simulation o'f'the supplying of direct ourrent by the generator driven by the engine. In the operation of an actual airplane the guns are not charged with shells and prepared for firing until the airplane is in flight and is approaching an area Where enemy action may be expected and therefore even though the pilot may have operated the Master armament switch 6H; and may have operated one of the gun selection switches, the trigger switch N5 is ineffective; This is a safeguard against the infliction 0t casualties which might occur while the airplane is on the carrier or is flying information;

In the trainer should the pilot operate the master armament switch 814 thereby operating the MA relay B06, operate one of the gun selection switches, for examples-witch 5H, thereby operating the INBD'relay 601, and then operate the trigger switch 61 5 thereby operating the TRG relay Si no circuit- Will be established for the GF relay in the sound efiects circuit 626} to cause the production of sound effects-representative of the firing of one or more of the guns.

It will now be assumed that during the simulated flight the pilot decides to simulate the preparation of the guns for firing. To charge the right guns he first rotates the knob l3 of the gun charger to the Charge position and then depresses the knob whereby it becomes locked in the Charge position. With the knob rotated to-thispositi'on the switch assembly 0 is released to its c position.- thereby establishing a circuit from ground over the lower back contact of the locking ground supply (15K) relay 62!, over the contacts of switch assembly C and through the RW Charge lamp at the instructors desk to battery', to inform: the instructor" that the pilot has operated thecharger for the-right guns to its Charge: position.

When the pilot depresses the knob i3, the

switch assembly B is operated to its alternate or position, and the assembly C remains released. With the switch assembly B in. its alternate position, a circuit is established from ground at the lower back contact of the LK relay 62!, over the contacts of switch B, over the inner lower nor-- mal contacts and through the winding of the CH relay 602 to battery. Relay 602 thereupon operates and locks over its inner lower alternate contacts and over the normal or 0 contacts of the switch assembly D to ground at the lower back contact of relay 62L Relay 662 thus remains operated until the guns are safetied and the switch assembly has become operated to its alternate or 0 position. V

Relay 602 upon operating establishes the cirouit for operating the CHI relay 603 if the hydraulic pressure simulated by the operation of the hydraulic pressure motor control circuit schematically illustrated by the rectangle is not less than 800 pounds per square inch. If there is simulated hydraulic pressure in the hydraulic system, the SYS relay ('13 will be operated and if the pressure is not less than 890 pounds per square inch, the medium pressure (relay 624) will be released and a circuit will be efiective for the hydraulic pressure (H-P) relay 625 which may be traced from ground over the back contact of relay 624, over the contacts of relay 623 and through the winding of relay 62s to battery. The simulation of hydraulic pressure for the trainer involving the control of relays 623, 624, 625 and 626, and the hydraulic motor control circuit 622 are fully disclosed in the application of F. M. Pearsall, Serial No. 622,069 filed concurrently herewith, and a more complete description of such apparatus is deemed unnecessary herein. Thus with relay 625 operated the circuit of relay 663 may be traced from ground over the upper back contact of the LK relay 625, over the inner upper front contact of relay 625, over the upper front contact of relay 662, through the inner lower normal contacts and winding of relay 663 and to battery. Relay 603 thereupon operates and looks over its inner lower alternate contacts to ground at the upper back contact oi relay 62L The operation of the CHI relay 6E3 simulates the application of pressure to the cylinders of the guns to pull out the bolts and to permit the gun charging mechanism of each gun to receive a shell.

With relay 663 operated a circuit is now es-- tablished for the RLS relay 665 which may be traced from battery through its winding, over the back contact of the CH2 relay 804, over the lower contacts of relay 603, over the next-to-inner upper contacts of relay 502, over the contacts of switch assembly B in the alternate or 0 position and to ground at the lower back contact of relay 62 I. Relay 665 upon operating connects potential from a 40-volt source of alternating current of phase 2 through resistance 62! and over its lower contacts and through resistance 628 to ground from which potential divider potential is applied to control conductor 629 of the hydraulic pressure motor control circuit 622 which will cause such circuit to operate in a manner representative of a change in the simulated pressure in the hydraulic system of the trainer. Relay 605 also establishes a circuit for solenoid 4! of the gun charger which may be traced from the source 636 of alternating current, through the winding 4! of the solenoid, over the inner upper contacts of relay 605 and over the upper contacts of relay 625 to ground. The operation of the solenoid 4] to release the charger knob l3 simulates the building up of pressure in the charger valve of an actual airplane to a point where the knob would be released and pressure in. the gun charging cylinders would be released to allow the bolts to restore and shells to be forced into the breeches of the guns ready for firing.

With the switch assembly B now released, a circuit is effective for the CH2 relay 663 which may be traced from ba tery through the winding of such relay, over the inner upper contacts of relays 663 and 602 and over the normal or 0 contacts of switch B to ground at the lower back contact of relay 52!. As soon as the RLS relay 665 operates, the trigger circuit is made effective over the upper contacts of such relay and is sustained over the lower contacts of the CH2 relay 604 after relay 604 operates and releases relay 665i. Relay 665, upon releasing when the knob i3 restores, opens the circuit of solenoid ii and removes the phase o2 hydraulic pressure drain potential from control conductor 629 of the hydraulic pressure motor control circuit 622.

It will be assumed, however, that the pilot does not yet wish to fire the guns but decides to safet them for the time being. To do this he turns the knob i3 out of the Charge position into the Safety position. Upon leaving the Charge position the switch assembly C is permitted to release thereby opening the previously traced circuit for the RW Charge lamp at the instructors desk. When the switch reaches the Safety position, the switch assembly A is permitted to release into its 0 position thereby establishing a circuit from ground at the lower back contact of relay iiZi, over the contacts of switch A and through the RW Safe lamp at the instructors desk to inform the instructor that the pilot has taken steps to render the right guns safe.

When the knob i3 is now depressed, the switch A remains in its released position and switch assembly D becomes operated to its alternate position. The locking circuit of the CH relay 662 is now opened at the 0 contacts of switch D and rela 692 releases, if the simulated hydraulic pressure has not fallen below 800 pounds per square inch to release relay 625 and thus open the alternative locking circuit for relay 602. The release. of relay 602 is followed by the release of the CH2 relay 664. With the RLS relay 665 and the CH2 relay both released, the trigger circuit is rendered ineffective and the guns are thus safetied.

The depression of the knob also establishes a circuit from battery through the upper winding of the SF rela Gilt, over the 0 contacts of the switch assembly D to ground at the lower back contact of relay 6% and relay 6643, upon operating, locks in a circuit from battery through its lower winding and over its lower contacts, over the upper back contact of the CH relay 662 and to ground at the upper back contact of relay 62S. If the simulated hydraulic pressure is at least 800 pounds .21 square inch, which would be sufiicient to cause the charger cylinders of actual guns to pull out the bolts to safety the guns and which would be sufficient to operate the detent mechanism of the charger valve, relay 625wil1 be operated and, following the operation of relay 685;, the operating circuit of the SFi rela 66! will be established from ground over the upper back contact of relay 621, over the inner, upper front contact of relay 625, over 9 the upper contacts of relay 60.0, over the lower normal contacts and through the winding of rela Gill and through resistance 63! to battery. Relay 60!, upon operating, looks over its lower alternate contacts and over the upper back contact of relay 652 to ground at the upper back contact of relay 62| so that it will remain operated until the CH rela 602 is again operated to charge the guns.

With relay 60! operated, a circuit for the RLS relay 605 is established which may be traced from ground at the lower back contact of relay 62!, over switch D in its position, over the upper contacts of relay 60! and through the winding of relay 605 to battery. Relay 605, upon operating, establishes the circuit of solenoid M to withdraw the detent of the gun charger to permit the knob 63 to restore, and reapplies phase p2 hydraulic drain potential to control conductor 62!) of the hydraulic pressure motor control circuit 622 whereby such circuit functions in a manner representative of a reduction in pressure in the hydraulic system incident to ,safetying the guns. When the knob 13 snaps out the switch D restores to its normal position thereby opening the initial operating circuit of relay 600 and opening the circuit of the RLS relay 605. Relay 605 now releases but relay 600 remains operated under the control of the CH relay 602. Relay 605, upon releasing, releases the solenoid 4! and removes the hydraulic drain potential of phase m from control conductor 629 of the hydraulic pressure motor control circuit 622 representatiVe of the fact that the guns have become safetied and are no longer draining potential from the hydraulic system. When the RLS relay 605 was operated, the trigger circuit was not efiective because the CH relay 602 was not at the time operated.

It will now be assumed that the pilot desires to simulate the placing Of the guns in condition for firing. To do so he now turns the gun charger knob to the Charge position. The switch assembly A is now operated to the 0 position thereby extinguishing the RW Safe lamp at the instructors desk and the switch assembly 0 is operated to the 0 position thereby establishing the circuit of the RW Charge lamp at the instructors desk. With switch C in the 0 position and with the CH! relay 602 still locked up, a circuit is established from ground at the lower back contact of relay 6 2!, over the contacts of switch C, over the upper contacts of relay 603 and over the inner lower normal contacts and through the winding of relay 602 to battery.

Relay 602 now operates and looks over its inner lower alternate contacts, over the contacts of switch assembly D in its normal or 0 position and to ground at the lower back contact of relay 62!. Relay 602, upon operating, opens at its up per back contact the locking circuits of the SF and SF'I relays 600 and SUI which new release. Relay 602 now establishes the circuit of the CH2 relay 604 which may be traced from battery through its winding, over the inner upper contacts of relays B03 and 602 and over the normal contacts of the switch assembly D to ground at the lower back contact of relay 62! The trigger circuit is now effective Without pushing the knob l3 in.

If the knob I3 should be depressed thereby operating the switch assembly B to its alternate position, rely 60 would be released and the previously traced circuit for the RLS relay 605 would be established over its upper back conguns functions in the same manner, supervision of such charger being secured at the instructors desk by the lighting of other lamps LW Charge and LW Safe.

To fire any of the guns the Master armament switch 694 must first be closed thereby causing the operation of the MA relay 606 which upon operating establishes a circuit from ground over its upper contacts and through the master armament switch lamp MAS at the instructors desk.

to inform the instructor that the pilot has closed the Master armament switch. It will be assumed thatv the pilot now selects the outboard guns for:

firing by operating the Outboard gun selection switch 6l3 thereby establishing a circuit from ground over the contacts of such switch and through the winding of the OTBD relay 609- to battery. Relay 609, upon operating, now establishes a circuit from ground over its upper contacts and through the OTBD lamp at the instructors desk to inform the instructor that the pilot.

has selected the outboard guns for firing.

When now the pilot closes the trigger switch 615 located on the upper end of the control stick: and the TRG relay 6l9 operates over an obvious. circuit, the closure of a trigger circuit for, firing; This circuit.

the outboard guns is simulated. may be traced from ground over the upper inner contacts of either relay BIO or relay 6l8, over the lower contacts of relay 606, over contacts of the Disable gun switch at the instructors desk, over' the upper contacts of the TRG relay M9, over the lower contacts of the CH2 relay 604, which itwill be recalled operated to simulate the charged. condition of the guns, over the lower contacts of the OTBD relay 609 and through the winding of the gun firing (GF) relay of the sound effects circuit 620 to battery. Relay GF thereupon op-' crates and in the manner fully disclosed in the application of R. H. Gumley Serial No. 622.065 filed concurrently herewith, the sound efiects circuit is rendered efiective to produce sounds inthe loudspeaker system of the trainer, simulating the noise of gun fire. The TRG relay 649 also closes over its lower contacts a circuit forthe Trigger lamp at the instructors desk to inform the instructor that the pilot is attempting to fire the outboard guns as indicated by the lighted OTBD lamp. The instructor will know if this attempt is sucessful if he hears'gun fire noise in the loudspeaker system.

The pilot may select the inboard or middle guns for firing by operating either the Inboard or the Middle gun selection switches 6H or BIZ thereby operating either th INBD or the MID relay Bill or 608 or he may fire any combination of the guns by operating difierent combinations of the switches 6H, BIZ or (H3.

The pilot may safety the guns before charging them by operating each gun charger to its safety. position whereupon the associated SF relay 600 is operated as previously described upon the operation of the switch assembly D to its alternate or 0 position. The relay 600 looks in a circuit over the upper back contact of the CH relay 602 and establishes the previously traced circuit for the SFI relay Sill which also operates and locks in a circuit over the upper back contact of relay 6132. A circuit at this time is established for the CHI relay 603 if hydraulic pressure .-is at; least- 800 pounds per square inch as represented by the.

operated condition of the 1-1-1? relay 625. The circuit of relay 683 may be traced from ground over the inner upper contacts of relay 525, over the inner upper contacts of relay Gill and through the inner lower normal contacts and through the Winding of relay 603 to battery. Relay 603 now looks to ground at the upper back contact of relay 62!. With relay GUI operated a circuit is established from battery through the RLS relay 805, over the upper contacts of relay Bill and over the alternate contacts of the switch assembly D to ground at the lower back contact of relay 62L Relay 60! thereupon operates to apply a hydraulic pressure drain potential to control conductor 629 of the hydraulic pressure motor control circuit 622 and to cause the energization of the solenoid 4| to release the knob l3 of the gun charger.

Should the simulated hydraulic pressure fail and the H-P relay 625 consequently release, when the SF, SF! and CHI 600, Bill and 603 are operated to denote that the guns have been safetied such relays will remain operated since they are all looked over the upper back contact of the CH relay B03 and the guns will stay in their safety conditions. The guns can still be charged by turning the gun charger knob l3 to its Charge position in which the switch assembly C is released to its position and the circuit of the CH relay 602 is established from ground at the lower back contact of relay 62!, over the contacts of switch assembly C, over the upper contacts of operated relay 603 and through the inner lower normal contacts and Winding of relay 602 to battery. Relay 602 operates, looks over its inner lower alternate contacts, over the inner upper back contact of relay 625 to ground at the upper back contact of relay 62 I, opens at its upper back contact the locking circuit of the SF and SM relays 600 and 60! which release, and establishes the circuit of the CH2 relay 804 which may be traced from battery through the winding of relay 604, over the inner upper contacts of relays 603 and 602, over the normal contacts of the switch assembly B and to ground at the lower back contact of relay 621. The guns are now charged and may be fired.

It is not necessary for the pilot to depress the gun charger knob l3 to charge the guns at this time but if he does the CH2 relay if operated will be released and the RLS relay 605 will be operated upon the movement of the switch assembly B to its alternate position. The solenoid M will be operated to release the gun charger knob and a drain potential will be added to'the control conductor 629 of the hydraulic pressure motor control circuit 632 in the manner previously described. As soon as the knob is released, relay 605 will release and relay 6M will reoperate to signify that the guns are in a charged condition.

If the hydraulic pressure is below 800 pounds per square inch and the pilot attempts to initially safety the guns, he can not do so because the SFI relay GUI will not operate followin the operation of relay 600 when the gun charger is operated to its Safety position since the circuit of relay GM is opened. with relay S25 released. Also if the pilot attempts to initially charge the guns he can not do so because the CI-ll relay 603 will not operate following the operation of relay 602 when the gun charger is operated to its Charge position, since the circuit of relay 603 is opened with relay 625 released. Since relay 603 can not operate the CH2 relay 604 can not operate to permit the pilot to close the trigger circuit. Since neither relay GUI nor 503 can be operated, the

RLS relay 605 can not operate and the knob if' depressed will remain locked in its depressed condition and no drain potential is applied to the control conductor 629 of the hydraulic pressure motor control circuit 522. This simulates the condition when the hydraulic pressure is too low to operate the gun charging mechanisms to pull back the bolts to either charge or safety the guns.

If the guns are assumed to be in the charged condition at the time the hydraulic pressure fails, it will be impossible for the pilot to safety them since the CH relay 602 will remain looked over the upper back contact of relay 625 to ground and the upper back contact of relay E2! and when the SF relay 600 becomes operated when the gun charge knob is turned to the Safety position and depressed, the SF! relay can not operate and as a consequence the RLS relay 605 can not be operated to release the knob from its depressed Safety position. With relay 602 operated the CHI and CH2 relays 603 and 604 both remain operated and the trigger circuit remains effective. This simulates the condition when the hydraulic pressure is too low to pull back the bolts of the guns after they have been charged.

The instructor may disable the guns at any time by opening the Disable gun switch and may simulate the exhaustion of ammunition for the guns by operating the Reload and charge key thereby operating the LK relay 62| which releases all operated relays in the gun charging circuits thereby restoring such circuits to normal;

What is claimed is:

1. In apparatus in a trainer for simulating the operations incident to the operation of a gun charger control, a rotatable and depressible gun charger control, a relay operable in response to the rotation and depression of said control, means for locking said control in its depressed position, a magnet for releasing said locking means, a trigger switch, and a relay operable in response to the operation of said first relay to cause the operation of said release magnet and to render said trigger switch efiective.

2. In apparatus in a trainer for simulating the hydraulic control of a gun charger by a gun charger control valve, means for simulating the production of a hydraulic pressure adequate to operate the charger of a gun, a rotatable and depressible gun charger control forsimulating a gun charger control valve, a relay operable in re sponse to the rotation and depression of said con trol, means for locking said control in its depressed condition, a magnet operable for releasing said locking means in simulation of the opening of the release port of a gun charger valve when a pressure is reached adequate to operate the gun charger, a trigger switch and a relay operable in response to the operation of said first relay if said hydraulic pressure simulating means is in a condition representative of said adequate pressure to cause the operation of said release magnet and to render said trigger switch effective.

3. In apparatus in a trainer for simulating the hydraulic control of a gun charger by a gun charger control valve, means for simulating the production of a hydraulic pressure adequate to operate the charger of the gun, a rotatable and depressible gun charger control for simulating the gun charger control valve, a relay operable in response to the rotation and depression of said control means for locking said control in its depressed condition, a magnet operable for releasing said locking means in simulation of the opening of the release port of a gun charger valve tive, and means controlledby said Ia tt'erI ela-y to simulate the reductionin hydraulic" pressure ill-- cident-tochargingagun. 7 v 4'. In apparatus in a trainer for simulating the hydraulic control of a gun charger by a gun char'ger control valve, means for" simulating the production of a hydraulic pressure adequate tooperate the charging mechanism of a-gun, a rdtatableand depressible gun charger'control for simulating a gun charger control valve, a'relay operable in response to the rotation and depression of said controh means, for locking said control in its depressed condition, a magnet operable for releasing. said locking.- means: in simulation of the opening of the release portvofi at gimz'charger valve whena-pressure. is-reached adequate to operate the gun charger, a trigger switch, a relay operable in response to the operation of said first relay said hydraulic pressure simulatingmeans is in a condition representative of said adequate pressure to cause the operation of said release magnet, and :a relayoperable in response-t'o the restoration of said control for rendering said trigger switch effective in simulation of the release of pressure in said gun charging mechanism which would render the gun ready for firing.

5. In apparatus in a trainer for simulating the operations incident to the operation of a gun charger control, a gun charger control rotatable to a gun safetying position and then depressible, a relay operable in response to the rotation and depression of said control, means for locking said control in its depressed condition, a. magnet for releasing said locking means and a relay operable in response to the operation of said first relay to cause the operation of said release magnet in simulation of the completion of safetying of a gun.

6. In apparatus in a trainer for simulating the hydraulic control of a gun charger by a gun charger control valve, means for simulating the production of a hydraulic pressure adequate to pull back the bolt of the gun to safety the gun, a gun charger control rotatable to a gun safetying position and then depressible for simulating a gun charger control valve. a relay operable in response to the rotation and depression of said control, means for locking said control in its depressed position, a magnet operable for releasing said locking means in simulation of the increase in hydraulic pressure to a value adequate to pull out the bolt of a gun, a relay operable in response to the operation of said first relay if said hydraulic pressure simulating means is in a condition representative of said adequate pressure to cause the operation of said release 'jmagnet, and means controlled by said latter relay to simulate the reduction of hydraulic pressure incident to pulling back the bolt of a gun to safety the gun.

'7. In apparatus in a trainer for simulating the hydraulic control of a gun charger by a gun charger control valve, means for simulating the production of a hydraulic pressure adequate to charge a gun or to safety it, a gun charger control rotatable to either a charge or to a safety position and then depressible, means for locking said control in its depressed position, a magnet operable for releasing said locking means in simulation ofth' e epenmger the release: port or 'a' g charger 'valye when a pressure is-rea'ched-adc quate to operate a gun charger to charge*'the gun, a relay operable when said control is rotated toits:

; charge position and then depressed, a trigger switcln a second. relay operable in response tothe operationof said first. relay if said hydraulic pressure-si mulating means is in a condition representati've of said adequate pressure tocause the operation of said release magnet, a relay operable in response to the restoration of said control in simulation of the release of pressure in said gun chargenfor'rendering said trigger switch efi'ec-- tive; means for releasing said latter relay if said control is-rotated to its safety position and thendepressed to' render said trigger switch ineffectire, and a relay operable when said control is rotated to -its safety position and then depressed forcausing the reoperation of said second relay to release said-control from itsdepressed positibn.

8, apparatus in a trainer for simulating-the hydrauliccontrol of" a gun charger by agun chargencontrol valve; means for simulating the operable insimulation of the application of"hy=--' draulic pressure to a gun charger adequate to charge or to safety the gun for releasing said looking means, a first relay operable when said control is rotated to its charge position and then depressed, a second relay operable when said control is rotated to its safety position and then depressed, a relay operable in response to the operation of either said first or said second relay if said hydraulic pressure simulating means is in the condition representative of said adequate pressure to cause the operation of said release mag net, a trigger switch, and a relay responsive to the restoration of said control from its depressed charge position for rendering said trigger switch effective, said latter relay being released to render said trigger switch ineffective if said control is depressed in its safety position subsequent to being released from its charge position.

9. In apparatus in a trainer for simulating the hydraulic control of a gun charger by a gun charger control valve, means for simulating the production of a hydraulic pressure adequate to charge a gun or to safety it, a gun charger control rotatable to either a charge or to a safety position and then depressible, means for locking said control in its depressed position, a magnet operable in simulation of the application of hydraulic pressure to a gun charger adequate to charge or to safety the gun for releasing said locking means, a first relay operable when said control is rotated to its charge position and then depressed, a second relay operable when said control is rotated to its safety position and then depressed, a relay operable in response to the operation of either said first or said second relay if said hydraulic pressure simulating means is in a condition representative of said adequate pressure to cause the operation of said release magnet, a trigger switch, and a relay responsive to the operation of said first relay following the release of said control from its safety position and its rotation into its charge position for rendering said trigger switch efiective.

10. In apparatus ina trainer for simulating the operations incident to the control of a plurality of guns, a master armament switch, a plurality of 15' gun selection switches, a gun charger control, means responsive to the operation of said control into a position simulating the charging of said guns, a trigger switch, means for simulating the sound of gun fire, and a circuit controlled jointly by said master armament switch, by the operated gun selector switches, by said trigger switch and by said gun charger simulating means for rendering said gun fire simulating means efiective. 11. In apparatus in a trainer for simulating the operations incident to the control of a plurality of guns, a master armament switch, a plurality of gun selection switches, an instructors desk, lamps at said desk responsive to the operation of said switches for informing theinstructor as to which of said switches has been operated, a gun charger control, means responsive to the operation of said control into a position simulating the charging of said guns, a trigger switch, means for simulating the sound of gunfire, a circuit controlled jointly by said master armament switch, by the operated gun selection switches, by said trigger switch and by said gun charger simulating means for rendering said gun fire simulating means effective, and a switch at said instructors desk for rendering said circuit inefiective in simu lation of the failure of the guns to fire.

12. In apparatus in a trainer for simulating the operation incident to the control of a plurality of by said gun charger simulating means for ren- Number 16:; guns,. a-master armament switch, a plurality of gun selector switches, an instructor's desk, lamps at said desk responsive to the operation of said,

switches for informing the instructor as to which 7 of said switches has been operated, a guncharger dering said gun fire simulating means efiective.

RUSSELL BLBUCHANAN.

REFERENCES CITED The following references file of this patent:

v UNITED STATES PATENTS Name are of record in the Date, 2,023,488 2,332,4 119 2,375,004 2,382,777

White Oct. 19, 1943 Knowles May l, 1945 Dahlberg Aug.,14, 1945 Poppeneeul Dec. 10, 1935 

